A 92,XXXY Miscarriage Consecutive to a Digynic Triploid Pregnancy

Area of Science:

• Reproductive genetics
• Human embryology
• Prenatal diagnosis

Background:

• Recurrent abnormal pregnancies pose significant diagnostic challenges.
• Understanding the genetic basis of abnormal conceptions is crucial for reproductive counseling.

Observation:

• A patient presented with a polymalformed male fetus diagnosed via prenatal ultrasound, leading to termination.
• A subsequent pregnancy resulted in missed abortion with a visible embryo.
• Genetic analysis of both pregnancies revealed distinct ploidy abnormalities.

Findings:

• The first pregnancy showed digynic triploidy (69,XXY) confirmed by QF-PCR and cytogenetics.
• The second pregnancy exhibited tetraploidy (92,XXXY) with a specific parental allele contribution (PPMM genotype).
• This combination of digynic triploidy and PPMM tetraploidy is previously unreported.

Implications:

• This case underscores the impact of parental genomic dosage balance on fetal development and pregnancy viability.
• It contributes to the understanding of rare chromosomal abnormalities and their phenotypic consequences.
• Further research into genomic imprinting and parental contributions is warranted.